The present invention relates to the field of the detection of toxic materials in the environment.
The presence of environmental toxins such as chemical and biological agents can be a well known destructive threat to humans, animals and plant life in the environment. Rapid detection of such toxins is of the utmost importance in both the military and commercial sectors to maintain a healthy state of people and the environment. Threatening agents in a military, or even in a civilian environment, include nerve gas for example. In the civilian sector, terrorist attacks could result in the spreading of deadly poisons, and waste dumps could contain substances which should be further processed and disposed of to protect the environment. Such detection should often ideally be produced at a considerable distance from the site containing the toxic agent, such as from the air, where the close presence of the agent could be an immediate threat to the health of humans carrying out the detection process.
One suggested approach is to generate a moving gaseous body of particles suspended in a cloud like moving mass, which can be directed at a site suspected of containing target agents, such as one or more designated toxic materials. Such suspended particles could interact with the toxins to thereafter produce, upon illumination, a detectable effect such as fluorescence, phosphorescence or spectral absorption or reflectance of particular wavelengths of light. However, in certain situations, it is desirable to continuously monitor a particular known site for the presence of a toxin over a substantial period of time extending into the future, such as up to many weeks, so that the aforesaid cloud or moving body of detection agents would be dissipated, and thus no longer be continuously available to monitor the site. One such application could involve monitoring compliance with a disarmament agreement requiring removal of selected target agents from suspected sites within a political body.